Your old and reliable Mi Band has been updated with a heart-rate sensor and is now coming in the name of the Mi Band 1S. It has all those old features available in the old Mi Band like vibration, LED notifications, auto unlock when near your Mi Phone etc.
The Mi Band 1S has a bit different dimensions (37 x 13.6 x 9.9mm) as compared to the old Mi Band (36 x 14 x 9mm) and may also not fit in the old bracelet. It also weighs a half gram more than the old Mi Band and has an IP67 rating for dust and water protection.
For the juice it still has the 45mAh battery, same as that could be found in the old Mi Band but may not last up to 30 days due to the heart-rate sensor addition. It will be available in China from November 11 for CNY99 (Almost $16).
Source: Xiaomi’s Official Facebook Post